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Paleobiology & Biosignatures: November 2010


Through NAI's Minority Institution Research Support Program, scientists at the University of Puerto Rico and their collaborators have identified a unique record of an ancient meteorite impact event that is preserved in microstructures in detrital grains of quartz, zircon, and monazite in the Vaal River, South Africa. The sand samples were collected from the channel of the Vaal River near the two billion-year old Vredefort Dome impact structure, where impact-shocked minerals are known to occur in rocks.

This is the first report that impact shock-deformed minerals survive the process of uplift, erosion, and sedimentary transport. The unique mineral shock-deformation was documented by scanning electron microscopy at the University of Puerto Rico and the University of Wisconsin. The team's results are published in the current issue of the GSA Bulletin.

This result demonstrates that a record of an ancient impact event can be preserved in sedimentary rocks billions of years after the impact crater is eroded. This recognition provides a new method to search for evidence of missing impacts in sedimentary rocks throughout the geologic time scale. This new insight may lead to the identification of missing impact events that have been hypothesized to cause biological mass extinctions, and also impact events on the early Earth that may have influenced the rise of life. [Source: NAI Newsletter]

A three-day workshop using NASA Astrobiology Institute (NAI) remote communications tools, on "Molecular Paleontology and Resurrection: Rewinding the Tape of Life," will be held on 8, 9 & 10 November 2010. Real-time participation requires only an internet connection and is available to interested scientists from around the world. Participants will discuss "top down" origin of life research, which will ultimately allow us to rewind the evolutionary record of biochemical processes and assemblies.

Organized by John Peters and Loren Williams, PIs of the NAI's Montana State University and Georgia Tech teams, a primary goal of the workshop is to foster new interdisciplinary collaborations across the community.

Session topics will include

* Phylogenetic Studies on Key Enzymes Involved in Information Pathways and Metabolism
* The Evolutionary History of Protein Synthesis
* Minerals to Enzymes, Bridging the Gap Between Metal-Based Abiotic and Biological Chemistry
* Phylogenetic Reconstruction/Resurrection, A Glimpse into Extinct Biochemistry
* What Can Modern Biological Energy Transformation Systems Tell Us About Conditions on the Early Earth?
* Linking the Evolutionary Record to the Geological Record

The workshop is open to the worldwide science community and is accessible via internet browser. To receive information on how to connect to the workshop, register on the NAI website: http://astrobiology.nasa.gov/nai/ool-www/ . [Source: NAI]